Flat stock finishing machine



Nov. 30, 1965 J ROSS FLAT STOCK FINISHING MACHINE Filed May 18, 1964 JOHN ROSS J m M w M w w M 2 8 Mo m WW 0 l S R F2 v V E 1 RR IKR T II T /.\A /3 9 9 T 2 R I w F T w M/ 2 5 :Q I z 8 8 United States Patent 3,220,145 FLAT STOCK FINISHING MACHINE John Ross, Southfield, Mich., assignor to Midwest Supply and Manufacturing Company, Ferndale, Mich, a corporation of Michigan Filed May 18, 1964, Ser. No. 368,287 20 Claims. (0. 51-139) The present application is a continuation-in-part of my copending application, Serial No. 240,247, filed November 27, 1962.

The present invention relates to improvements in a machine for the abrasive finishing of flat stock, such as metal sheets, from end to end thereof in a manner to avoid the production of transverse shadow lines or visible highlight marks on the finished sheet. More particularly, the invention concerns a flat stock finishing machine of the abrasive belt and billy roll type, which machine has improved provisions for the manipulation of its billy roll in the finishing operation to eliminate the possibility of occurrence of the shadow lines or marks mentioned above. Damaging of the abrasive belt is also prevented.

In the operation of conventional finishing machines of this type, in which fiat metal sheets are advanced by driven pinch rolls into the bite between a backing or so-called billy roll and a high speed abrasive belt trained around a contact roll or drum directly above the backing roll, the leading edge of the sheet initially engages the abrasive belt just prior to passing into the nip or bite of the belt and the backing or billy roll. This has the effect of causing the sheets leading edge to tend to shave the granular particles of the belt on a transverse line across its width, i.e., parallel to the belt contact roll axis. The result is that the disturbed grain of the belt, in its succeeding polishing contact with the sheet, tends, by reason of the irregularity of abrasive particle distribution, to leave visible highlight marks or shadow lines on the sheet. The same effect is caused at the trailing edge of the sheet supported by the billy roll in passing beneath the belt, i.e., another disturbance of the belt grain takes place. The provisions of the present invention eliminate these possibilities, resulting in the production of finished sheets not subjected to the visible effects referred to.

It is an object of the invention to provide a hilly roll type of flat stock finishing machine, in which means are incorporated to successively shift the billy roll from an initial position in which its axis is disposed in forwardly offset relation to the axis of the belt contact roll, i.e., in the direction of advance of the sheet by the pinch rolls, to a rearwardly disposed offset position relative to the belt contact roll axis while the sheet is passing and after the sheet has passed the belt, without direct shaving contact of the sheet edge with the latter. Thus the sheet will ride up upon the billy roll in the forwardly disposed position of the latter, having first passed the vertical plane of the belt contact roll axis, and, the billy roll being then translated to the rear as polishing on the sheet proceeds, the rear end of the sheet will pass the vertical plane of the belt contact roll axis without exerting a parting shaving action on the belt grain.

Another object is to provide an improved flat stock finishing machine of the type described, including automatically acting means to shift the hilly roll forwardly to rearwardly and return forwardly, such means being shown as pneumatic, although hydraulic, electrical, mechanical and other equivalents, or combinations thereof, may be substituted, and in which the automatic control thereof is governed by the sheet itself. More specifically, the automatic provisions includes dual solenoids acting to reverse the operation of the billy roll shifting means.

A still further object is to provide apparatus as de- "ice scribed, in which the sheet is advanced toward the abrasive belt and billy roll by a conventional type of driven pinch roll structure, and discharged from the finishing belt by similar driven pinch roll means on the opposite longitudinal or forward side of the belt, the control of the automatically acting means for shifting the hilly roll in the desired manner originating at a control unit adjacent the first named pinch rolls, said unit being operatively connected to the automatic means in question. As shown herein, the control is photoelectrically derived from the traveling sheet itself to govern the action of the billy roll through illustrative electrical circuitry. However, it is to be understood that other types of billy roll actuation than through electrical agencies are contemplated, just as are equivalents of the illustrated pneumatic provisions.

Yet another object is to provide an improved billy roll type of fiat stock finishing machine and control means for variably positioning its billy roll, in which the apparatus may have its photoelectrically responsive controls wired for either a single pass, unidirectional finishing stroke of the sheet, or for a reversing, back-and-forth polishing stroke.

Generally, it is an object of the invention to provide apparatus which is entirely automatic in its operation to insure the finishing of sheet metal stock without the occurrence of shadow lines or high-lights referred to; and which makes possible a longer life of the finishing belt by avoiding the grain shaving action on the belt by the edges of the sheet.

A specific object is to provide means to adjust the stroke of the billy roll to determine its position in reference to the center line of the abrasive member.

The foregoing as well as other objects will become more apparent as this description proceeds, especially when considered in connection with the accompanying drawings illustrating the invention, wherein:

FIG. 1 is a highly schematic view showing suggested components for the control of the shifting of the hilly roll of a flat stock finishing machine for the above purposes; and

FIG. 2 is a schematic wiring diagram showing electrical circuitry responsive to certain photoelectric sensing components of FIG. 1 to control the position of the billy roll, this view also including means not directly germane to the present invention for controlling the drive of the pinch rolls, the tracking of the abrasive belt about its contact roll, etc.

Referring to FIG. 1 of the drawings, the reference numeral 10 generally designates the high speed abrasive finishing unit for the polishing of the top surface of a metal sheet S of predetermined width and length, this sheet being forwarded to the abrasive unit 10 in a conventional manner by a set of feed-in pinch rolls 12 arranged in vertically opposed pairs in longitudinally spaced relation to one another in the direction of feed of the sheet S, shown by the arrow in FIG. 1.

Assuming this to be the only or the first (in a reversing operation) direction of sheet feeding the terms forward, forwardly, front, and the like, will be considered for the sake of uniformity to be in the direction of the arrow; while the opposite direction will be referred to by the terms such as rearward, rearwardly and rear. The terms leading and trailing are of course used in conformity with the actual direction of travel, whether it be forward or rearward.

Upon leaving the abrasive finishing unit 10, the sheet S conventionally enters another set of discharge pinch rolls 14 which are located in pairs relative to one another, like the feed-in rolls 12, and are also driven positively by conventional motor means (not shown in FIG. 1, although reversing motor starter provisions appear in FIG. 2 and will be hereinafter referred to).

As in conventional fiat stock finishing machines, the sets of pinch rolls 12, 14 may be unidirectionally driven for a single passing of each sheet in the direction of the arrow of FIG. 1, or may be reversibly driven for multiple passes prior to discharge by the set of rolls 12; and the invention contemplates an automatic control of the billy roll shifting provisions, to be described, consistent with whichever of the two types of stock feed as may prevail. The illustrative wiring in FIG. 2 for the reversing operation involves, in addition to relay and other components common to the single-pass operation, the contacts of a conventional motor starter of the motorized drive for the pinch roll sets 12 and 14. However, as indicated above, various types of billy roll shifting means are contemplated.

The abrasive unit is of a well known type including an endless abrasive belt 16 trained at its bottom about a contact roller 18, and suitably driven at a further upper roller (not shown) at a high linear speed. However, in so far as the present invention is concerned, the unit 10 might be any conventional high speed rotary abrasive cylinder or drum type.

The billy roll of the apparatus is designated 20, and the invention contemplates the successive longitudinal shifting thereof from a position shown in solid line in FIG. 1, as the leading edge of the sheet S approaches contact roller 18, to the dotted line position, and vice versa. In the solid line position, the axis of the billy roll 20 is displaced or offset forwardly of the vertical plane through the axis of contact roller 18. In the dotted line position the billy roll axis is displaced rearwardly of that plane, in reference to the arrow direction of sheet feed in both instances, as indicated above. It is to be understood that the displacement of billy roll 20 in its two positions relative to the abrasive belt roller axis is exaggerated for the purpose of clarity. Actually, the shifting stroke of the billy roll from front to rear and vice versa will not eX- ceed two inches. However, this is sufiicient for the purposes of the invention, and will permit a tip-to-tip or endto-end polishing action on the sheet S without leaving perceptible shadow or high-lights on the sheet.

This is because of the fact that on the infeed stroke of sheet S, with billy roll 20 in the solid line position of FIG. 1, the forward edge of the sheet will, without significant edge engagement with the belt 16 and resultant shaving action of the latter, travel under the belt and contact roller 18, then ride up over the crown of billy roll 20 so as to cause grinding pressure to be applied on the top of the sheet.

On the other hand, with billy roll 20 shifted to the rear, dotted line position of FIG. 1 as the polishing proceeds, and after the leading end of sheet S has entered the nip of the discharge pinch roll set 14, the billy roll 20 continues to support the sheet until the rear or trailing edge of the latter has passed thereover, but not as the rear edge departs from belt 16; so that a second shaving action on abrasive belt 16 is again avoided. It is to be emphasized that the displacement of billy roll 20 on either side of the vertical plane of the axis of contact roller 18 is very slight; and a support for the application of highly uniform grinding pressure is afiforded, by the means to be described, when the billy roll is in either position, as well as the transitional phase when the hilly roll shifts from front to rear (or from rear to front in the event a reversing stroke is to be imparted to sheet S). If needed (as is unlikely), simple provision may be made to guide the billy roll for a stroke which is not strictly rectilinear, in order to achieve a uniformity of grinding pressure of the greatest possible precision.

As herein illustrated, in order to effect the shifting of billy r011 20, it is journaled on a supporting structure generally designated 22 in FIG. 1, which will maintain its axis at a uniform vertical distance from that of belt contact roller 18, such as will properly receive the sheet S between these rollers for the preservation of desired grinding pressure. The support 22 as shown includes a longitudinally extending actuator 24 reciprocable in a plane paralleling that of the sheet feed under the action of a billy roll shifting or transfer unit, generally designated 26, to be further described. Member 24 is supported for this reciprocatory motion by a hilly roll pick-up unit 28, shown to conventionally comprise a hilly roll pick-up cylinder 30 having a linkage 32 provided with an anti-friction support roller 34 upon which a bottom guide 36 of the billy roll actuator member 24 may ride. Other than in the fact that the hilly roll pick-up unit 28 will sustain the billy roll 20 for its desired reciprocatory shifting action, said unit is conventional. Provision may be made, as by an adjustable stop device 38, to limit as desired the extremes of the shifting action of the billy roll, as will be described.

The billy roll transfer unit 26 is shown schematically in FIG. 1 as comprising a pneumatic cylinder 40, to the plunger 41 of which the billy roll actuator member 24 is pivotally connected. Pneumatic pressure is applied to the opposite ends of cylinder through lines 42 from a conventional four-way, double solenoid-actuated valve 44, the intake to which may be controlled by a master valve 46. Valve 44 is operated to reverse the fluid flow in lines 42 by means of solenoids 48, 49 appearing in FIG. 2. Master valve 46 may be considered illustrative of suitable means by which the speed of the reversing stroke of the plunger 41 of cylinder 40 may be governed as desired.

Again referring to FIG. 1, the sheet S itself controls the automatic energization and de-energization of the solenoids 48, 49 (hence the reversing of a flow to pneumatic cylinder 40) in part through the agency of a photoelectric unit 50 including a light source 52 normally projecting a beam B down through the space between vertically arranged pairs of the sheet feed-in pinch rolls 20, this beam energizing a suitable photocell component 54 of photoelectric unit 50. When the beam B is interrupted by sheet S the unit 50 closes a normally open contact 50 in the circuit of FIG. 2, in a known manner.

Similarly, when a reversing stroke operation of the apparatus is contemplated, recourse is had to a second photoelectric unit 56 including a light source 58 adapted to project the beam B to a photocell device 60 in the zone between the discharge pinch roll sets 14. When sheet S interrupts beam B the photoelectric unit 56 closes a normally open contact 56' in the circuit of FIG. 2.

The billy roll transfer unit 26 has been identified as a pneumatically actuated one. However, those skilled in the art will appreciate that a hydraulic cylinder unit could also be employed, or an electrically actuated one, or even a mechanically operated one having appropriate connections to the hilly roll actuator 24. The important thing is that the position of billy roll 20 in its vertical relation to the belt contact roller 18 shall be substantially uniformly maintained in the longitudinally shifting of a billy roll to and from the opposite sides of roller 18. If greater uniformity of grinding pressure is required to insure an absolutely uniform grinding depth, it is contemplated that supplemental billy roll guide provisions may be made, such as will produce a stroke of the billy roll which is arcuate, i.e., upwardly concave in shape, in an extremely mild degree.

The device 38 appearing in FIG. 1 is employed to determine the distance of the longitudinal stroke of the hilly roll 20, as well as the position of the billy roll in reference to the center line of contact roller 18 in either the forward, solid line position of FIG. 1 or the rearward, dotted line position. That is, the finishing of certain types of sheet may make it desirable that the hilly roll axis be closer to the contact roller axis in the former position than in the latter, or vice versa; or it may be desirable that the sheet have a greater or lesser period of time in which it is unsupported by the billy roll in one or the other of the positions of the latter.

Therefore, the device 38, as schematically shown in FIG. 1, may comprise a suitable abutment or lug 62 can ried by the billy roll actuator 24, along with adjustable means engageable with opposite sides of such lug to adjustably limit the to-and-fro movement of the billy roll. As shown, such means comprises a support 64 suitably mounted for adjustment in the direction of movement of actuator 24, the adjustment being under actuation of a threaded stem 66 under manipulation of a hand wheel 67, the stem being appropriately journaled for rotation and held against axial movement. Support 64 in turn has opposed stops 68 mounted thereon for slidable adjustment toward and from one another on the support. Such adjustment may be effected by a reversely threaded screw member 70 manipulated by a hand wheel 72, movement of the screw 70 also being prevented in the axial direction.

FIG. 2 of the drawings is a schematic wiring diagram showing electrical control circuitry, in particular in the portion of the diagram bracketed as A, for the control of the reversing operation of billy roll 20 in response to the photoelectric provisions discussed above, and their associated relay and switch means. Also associated with the FIG. 2 circuit, at the power input side of the latter bracketed as B, are certain electrical provisions not primarily germane to the present invention, as for the control of the tracking of the abrasive belt 16 about its contact roller 18. Certain motor starting relay provisions are included in this portion, and will hereinafter be briefly mentioned. There have been omitted from FIG. 2, as being non-essential to an understanding of the basic control circuitry, certain sub-circuits involving solenoid and signal light means relating to the belt track control means, to motor braking provisions, to the signaling of lubrication conditions, and the like.

The reference numeral 74 in FIG. 2 designates a stepdown transformer supplied from a 220 volt line, the terminals of the secondary Winding 76 of this transformer being connected through fuses 78, 79 to the parallel supply and return leads 80, 82, respectively; and a master switch 84 is connected between one of the fuses and the supply lead 80.

Now referring to bracketed portion A of FIG. 2, the lead 80 connects through a secondary off-on manual control switch 86 with a secondary voltage supply lead 88, from which a number of parallel sub-circuits connect to the return lead 82. The sub-circuits are identified by reference numerals applied to electrical leads thereof.

The uppermost of these, designated 89, contains a control relay 1CR connected in series with the normally open contact 50' of a relay whose coil (not shown) is energized upon interruption of the beam B of the photoelectric unit 50, in a first traverse of the sheet S in its forward infeed to the left, as viewed in FIG. 1.

A second conductor or lead 91 has a corresponding, normally open contact 56 of the second or forwardmost photoelectric unit 56 connected therein in series with a second control relay 2CR, the contact 56' also closing when the beam B is interrupted by sheet S.

A third lead 93 extends between leads 88, 82 in parallel with lead 91. The lead 93 connects in series a normally open contact MP of a forward motor starter relay MF (whose coil appears in bracketed portion B of FIG. 2), the contact ICR' of control relay lCR and, as connected in parallel with each other, a first time delay relay 1TR and a second time delay relay 2T R. The solenoid 48 and the contact of timing relay 1TR are connected in series with one another about the control relay contact lCR' and time delay relay ITR. Timing relay contact 1TR delays in closing upon energization of relay ITR.

The contact ZTR of timing relay 2TR is connected by a further lead 95 across leads 88, 82 in series with a manual selector switch 97 and the second solenoid 49. The contact 2TR is a normally closed one which opens immediately upon energization of its coil.

A reversing contact MR of the reverse motor starter relay MR (portion B) is connected by another lead 99 in series with the contact 2CR' of control relay ZCR and a third relay 3TR, which comes into play only in the reversing operation of the unit 10. The normally open contact 3TR' of the last named relay is connected from between the starter contact MR and control relay contact 2CR to a point in lead between selector switch 97 and solenoid 49.

Parallel leads 101, 102 respectively connect the photoelectric units 50 and 56 across the supply and return leads 8'8 and 82.

In respect to the bracketed portion B of the wiring diagram, it includes inter-locking sub-circuitry, generally designated by the reference numeral 104, for forwarding and reversing drive of the motors operating the sets of pinch rolls 12, 12 and 14, 14, including the respective forward and reverse motor starters MF and MR referred to above and the respective contacts MF" and MR" thereof. Wired in this circuitry are a manually actuated stop switch 106, and double contact forward and reverse manual switches 107, 108, respectively. It is believed that the operation of these components in the control of the forwarding and reversing drive of the pinch rolls will be understood by those skilled in the art.

A third photoelectric unit is connected across the main supply and return conductors or leads 80, 82, this unit being involved solely in the control of the tracking of the abrasive belt; and also involved in this function are a third control relay 3CR and its contact 3CR', as well as start and stop switches 112, 113, respectively. These relate to belt tracking control.

Further improvements of the control circuitry of FIG. 2 are possible, for example provisions for automatic sequencing of the hilly roll shift or transfer as to direction, and appropriate switch means to change the operation from manual to automatic and vice versa. However, illustration of these features has been omitted from FIG. 2 in the interest of simplicity, and it will be assumed that the operation of the forward and reverse pinch roll motor starters MF and MR is manual.

Operation-Single stroke With master switch 84 closed, motor stop switch 106 closed, dual or ganged switch 107 closed (dotted line in FIG. 2), ganged reversing switch 108 in dotted line position, and the selector switch 97 set, as in FIG. 2, for single stroke operation, an attendant manually initiates operation of the system by operating forward motor starter relay MF, with the result that the feed-in pinch rolls 12 operate to advance the sheet S to the left (FIG. 1), and the forward starter contact MP is closed. The leading edge of the sheet first breaks the beam B of phototube unit 50, causing the closure of the phototube relay contact 50 and energization of control relay lCR.

The resultant closure of control relay contact 1CR' in lead 93 completes a circuit including that contact, the closed forward motor starter contact MF and the parallel-connected time delay relays 1TR and 2TR. As indicated above, the contact lTR in the associated shunt circuit delays in closing to energize the first solenoid 48 until the advancing edge of the sheet S enters the nip of the first pair of the forward-most or left-hand set of feed rolls 14, so that the hilly roll 20 remains in its solid line position of FIG. 1 until this occurs. On the other hand, the contact 2TR' of timing relay 2TR opens immediately upon energization of the latter, so that the second solenoid 49 is de-energized at the outset of operation.

As the sheet enters the nip of the first of the left-hand pinch rolls 14, relay 1TR times out to close its contact 1TR, thus energizing solenoid 48, with the result that valve 44 is operated to cause actuator 26 to draw billy roll 20 to the right (FIG. 1) to its dotted line position, where it remains until the forward motion of sheet S to the left is completed in single stroke operation.

As the trailing edge of the sheet S passes phototube beam B, the restoration of the latter causes de-energization of phototube unit 50, with consequent opening of the contact 50 and de-energization of control relay lCR. This re-opens contact ICR', tie-energizing the delay relays 1TR and 2TR, whereupon the contact lTR' of the former drops out immediately, de-energizing solenoid 48. As the leading edge of sheet S interrupts beam B the photoelectrically responsive contact 56' in lead 91 is energized, thus energizing the second control relay 2CR.

After a time delay sufficient to allow the sheet S to clear billy roll 20, the contact 2TR' of timing relay 2TR recloses, and the second solenoid 49 is energized. This results in the operation of actuating device 26 to restore billy roll 20 to its original, left-hand position forwardly of the axis of belt contact roll 18; and the apparatus is ready for the passing of another sheet in single stroke operation.

Reversing stroke operation The selector switch 97 is operated to a reversing setting, i.e., to open switch 97 and the sub-circuit containing timing relay contact 2TR only up to the second solenoid 49; leaving the latter connected in a circuit including the reversing motor starter contact MR, the contact 2CR' of control relay ZCR, the third timing delay relay 3TR and the normally open contact STR' of the latter. Upon manual operation of the forward motor starting relay MP for the initial phase of reversing operation, a circuit is completed in lead 93 through forward motor starter contact MP, the contact ICR' of control relay 1CR, thus energizing time delay relays lTR and ZTR, as before; and the delayed closing of contact lTR' keeps solenoid 48 de-energized until the leading edge of sheet S passes the vertical center line of belt contact roll 18. Timing relay ZTR of course closes immediately, but this is of no effect since its contact ZTR' is in the circuit of lead 95 opened at selector switch 97. As delay relay contact lTR' closes, solenoid 48 is energized, resulting in movement of the hilly rol-l rearwardly, or to dotted line posi tion right of the contact roll center line, as in single stroke operation.

When beam B is restored by passage of the trailing edge of the sheet, photoelectric unit 50 causes opening of the contact 50, the relay 1CR is de-energized, and its contact 1CR' drops out to de-energize timing relay lTR. The contact lTR' of the latter reopens immediately to de-energize solenoid 48, but the billy roll 20 remains to the remote (right in FIG. 1) of the axis of contact roll 18.

When the motor starter contact relay MR is now manually operated, the second beam B is broken by the leading edge of the sheet S, now moving to the right, and the result is to close the second, phototube responsive contact 56' and energize control relay ZCR. Its normally open contact 2CR' closes to energize the third time delay relay 3TR.

The contact 3TR of the last named relay delays in closing until the leading edge of the sheet S passes the contact roll axis, moving to the rear. At such time contact 3TR' closes to energize the second solenoid 49, which thereupon occasions operation of actuator unit 26 to shift or transfer billy roll 20 back to the left of the contact roll center line, its original position when reversing operation commenced. The apparatus is now ready for another reversing cycle, upon operation of starter relay MP, or for a single stroke operation upon restoral of selector switch 97 to the solid line position of FIG. 2 and manual operation of relay MP.

The apparatus and its controls are extremely simple and inexpensive, yet reliable and capable. of being installed readily in various embodiments on a billy roll type of flat stock finishing machine. Positive action in controlling shift of the billy roll 20 from one side of the axis of contact roll 18 to the other, in properly timed relation to the travel of the sheet S in either single or reversing stroke operation, is insured by the dual solenoid arrangement of FIG. 2.

Elimination of local physical engagement of the leading and trailing edges of the sheet with the abrasive member of the finishing unit 10 eliminates the destructive shaving action on the abrasive of the unit with resultant increased belt life, and also eliminates the undesirable shadow lines or high-lights on the finished stock which have heretofore been considered inevitable in equipment of this type.

What I claim as my invention is:

1. Apparatus for finishing fiat sheet stock, comprising a rotatively driven abrasive supporting member, means to feed the stock flatwise past said member in a plane paralleling the axis of rotative drive of the latter for a finishing operation on said stock by said member, a backing roll rotatable on an axis paralleling said drive axis to sustain said stock during said feed and finishing operation, and means operating in timed relation to the feed of the stock to move. said backing roll to and from a position in which the backing roll axis is, at the commencement of the finishing operation, forward of the drive axis of said member, in respect to the direction of feed of the stock.

2. Apparatus for finishing flat sheet stock, comprising a rotatively driven abrasive supporting member, means to feed the stock flatwise past said member in a plane paralleling the axis of rotative drive of the latter for a finishing operation on said stock by said member, a backing roll rotatable on an axis paralleling said drive axis to sustain said stock during said feed and finishing operation, and means to temporarily support said backing roll during said feed in an initial position in which the backing roll axis is, at the commencement of the finishing operation, forward of the drive axis of said member, in respect to the direction of feed of the stock, and to then move said backing roll to a more rearward position of its axis as finishing proceeds.

3. Apparatus for finishing flat sheet stock, comprising a rotatively driven abrasive supporting member, means to feed the stock flatwise past said member in a plane paralleling the axis of rotative drive of the latter for a finishing operation on said stock by said member, a backing roll rotatable on an axis paralleling said drive axis to sustain said stock during said feed and finishing operation, and means to temporarily support said backing roll during said feed in an initial position in which the backing roll axis is, at the commencement of the finishing op eration, forward of the drive axis of said member in respect to the direction of feed of the stock, and to then move said backing roll to a more rearward position of its axis on the opposite side of the drive axis of said member as finishing proceeds.

4. Apparatus for finishing fiat sheet stock, comprising a rotatively driven abrasive supporting member, means to feed the stock flatwise past said member in a plane paralleling the axis of rotative drive of the latter for a finishing operation on said stock by said member, a backing roll rotatable on an axis paralleling said drive axis to sustain said stock during said feed and finishing operation, and means to temporarily support said backing roll during said feed in an initial position in which the backing roll axis is, at the commencement of the finishing operation, forward of the drive axis of said member, in respect to the direction of feed of the stock, to then move said backing roll to a more rearward position of its axis on the opposite side of the drive axis of said member as finishing proceeds, and to return said backing roll fo wardly to said initial position after the trailing edge of the sheet has passed the drive axis of said member.

5. In flat stock. finishing apparatus of the type having a rotatively driven abrasive supporting member, means to feed the stock past said member in a plane paralleling the axis of rotative drive of the latter for a finishing operation on said stock by said member, and a rotative backing roll to sustain said stock against said member during said feed and finishing operation, the improvement comprising means operating in timed relation to the feed of the stock to move said backing roll to and from a position in which the backing roll axis is forward relative to the drive axis of said member in respect to the direction of feed of the stock.

6. In fiat stock finishing apparatus of the type having a rotatively driven abrasive supporting member, means to feed the stock past said member in a plane paralleling the axis of rotative drive of the latter for a finishing operation on said stock by said member, and a rotative backing roll to sustain said stock against said member during said feed and finishing operation; the improvement comprising means to support said backing roll in a position in which the backing roll axis is forward relative to the drive axis of said member, in respect to the direction of feed of the stock, and means responsive to signal from said stock in the feed of the latter to move said backing roll to a more rearward position relative to the drive axis of said member, and to thereafter restore said backing roll to said first named relative position thereof.

7. Apparatus for finishing flat sheet stock, comprising a rotatively driven abrasive supporting member, means feeding the stock fiatwise past said member in a direction paralleling the drive axis of the latter for a finishing operation on said stock by said member, a backing roll supported in transversely spaced relation to said member for rotation on an axis paralleling said drive axis to sustain said stock during said feed and finishing operation, and means to effect relative bodily movement of said member and said backing roll between positions in which the backing roll axis is forward of the drive axis of said member, in respect to the direction of feed of the stock, to a more rearward position relative to said drive axis.

' 8. Apparatus for finishing flat stock, comprising a rota: tively driven abrasive supporting member, means to feed the stock fiatwise past said member in a plane paralleling the drive axis of the latter for a finishing operation on said stock by said member, a backing roll rotatable on an axis paralleling said drive axis to sustain said stock during said feed and finishing operation, means to move said backing roll from a position in which the backing roll axis is in a position forward of the drive axis of said member, in respect to the direction of feed of the stock, to a more rearward position on the opposite side of said drive axis, and vice versa, and means operatively connected to said last named means to govern the reversing operation thereof under the control of said stock.

1 9. Apparatus for finishing flat sheets, comprising a rotatively driven abrasive supporting member, means to feed a sheet fiatwise past said member in a plane paralleling the rotative drive axis of the latter for a finishing operation on said sheet by said member, a backing roll rotatable on an axis paralleling said drive axis to sustain said sheet during said feed and finishing operation, means to move said backing roll from a position in which the backing roll axis is in a position forward of the drive axis of said member, in respect to the direction of feed of the sheet, to a more rearward position on the opposite side of said drive axis, and vice versa, and means operatively connected to said last named means to govern the reversing operation thereof under the control of said sheet, including means responsive to signal from the leading and trailing edges of the sheet to control said governing means.

10. In a flat stock finishing machine characterized by an abrasive belt guided by a contact roller, a billy roll rotatable on an axis paralleling that of the contact roller to sustain the stock for a finishing operation by said belt as the latter rounds said contact roller, and means to feed the stock fiatwise between said belt and billy roll; the improvement comprising means to effect relative movement of said billy roll and contact roller in a direction generally paralleling the surface of the stock and between positions in which the axis of one thereof is offset forwardly and rearwardly in reference to a parallel plane which includes the axis of the other thereof and is upright to the surface of the stock, and means controlled by said stock in the feed thereof to control said relative movement of the billy roll and contact roller.

11. In a flat stock finishing machine characterized by an abrasive belt guided by a contact roller, a hilly roll rotatable on an axis paralleling that of the contact roller to sustain the stock for a finishing operation by said belt as the latter rounds said contact roller, and means to feed the stock fiatwise between said belt, and billy roll; the improvement comprising means to effect relative move ment of said billy roll and contact roller in a direction generally paralleling the surface of the stock and between positions in which the axis of one thereof is offset forwardly and rearwardly in reference to a parallel plane which includes the axis of one thereof and is upright to the surface of the stock, and means controlled by said stock and responsive to signal from the leading edge thereof in the feed thereof to control said relative movement of the billy roll and contact roller.

12. Apparatus for finishing fiat sheet stock, comprising a rotatively driven abrasive supporting member, means feeding the stock fiatwise past said member in a plane paralleling the drive axis of the latter for a finishing operation on said stock by said member, a backing roll rotatable on an axis paralleling said drive axis to sustain said stock during said feed and finishing operation, means to support said backing roll during said feed in a position in which the backing roll axis is, at the commencement of the finishing operation, forward of the drive axis of said member, in respect to the direction of feed of the stock, and means to adjust said forward position of said backing roll relative to said drive axis in a direction paralleling that of said feed.

13. Apparatus for finishing flat sheet stock, comprising a rotatively driven abrasive supporting member, means feeding the stock fiatwise past said member in a plane paralleling the drive axis of the latter for a finishing operation on said stock by said member, a backing roll rotatable on an axis paralleling said drive axis to sustain said stock during said feed and finishing operation, means to temporarily support said backing roll during said feed in an initial position in which the backing roll axis is, at the commencement of the finishing operation, forward of the drive axis of said member, in respect to the direction of feed of the stock, and then to move said backing roll to a more rearward position of its axis as finishing proceeds, and means to adjust said forward and rearward positions of said backing roll relative to said drive axis of said member in a direction paralleling that of said feed.

14. Apparatus for finishing flat sheet stock, comprising a rotatively driven abrasive supporting member, means feeding the stock fiatwise past said member in a plane paralleling the drive axis of the latter for a finishing operation on said stock by said member, a backing roll rotatable on an axis paralleling said drive axis to sustain said stock during said feed and finishing operation, means to temporarily support said backing roll during said feed in an initial position in which the backing roll axis is, at the commencement of the finishing operation, forward of the drive axis of said member, in respect to the direction of feed of the stock, and then to move said backing roll to a more rearward position of its axis as finishing proceeds, and means to adjust said forward and rearward positions of said backing roll relative to said drive axis of said member and relative to one another in a direction paralleling that of said feed.

15. Apparatus for finishing flat sheet stock, comprising a rotatively driven abrasive supporting member, means for feeding the stock fiatwise past said member in a plane paralleling said drive axis for a finishing operation by said member on said stock, a backing roll rotatable on an axis paralleling said drive axis to sustain said stock during said finishing operation, means to control a relative placement of said member and backing roll during the stock feeding in an initial condition in which the backing roll axis is, at the commencement of the finishing operation, forward of the drive axis of said member in respect to the direction of feed of the said stock, and then to a placement in which said backing roll axis is in a more rearward relative position as finishing proceeds, said control means comprising an operating device to effect said relative sheet placement, a photoelectric unit adapted to be operated in response to alteration of its beam by said sheet, and means responsive to operation of said unit to actuate said operating device for said relative forward-to-rearward placement of said backing roll.

16. Apparatus for finishing flat sheet stock, comprising a rotatively driven abrasive supporting member, means on a side of the axis of drive of said member for feeding the stock fiatwise past said member in a plane paralleling said drive axis for a finishing operation by said member on said stock, a backing roll rotatable on an axis paralleling said drive axis to sustain said stock during said finishing operation, means to control a relative placement of said member and backing roll during the stock feeding in an initial condition in which the backing roll axis is, at the commencement of the finishing operation, forward of the drive axis of said member in respect to the direction of feed of the said stock, and then to a placement in which said backing roll axis is in a more rearward relative position as finishing proceeds, said control means comprising an operating device to effect said relative sheet placement, a photoelectric unit disposed on the side of said rotatively driven member adjacent said feed means and adapted to be operated in response to alteration of its beam by said sheet, and means responsive to operation of said unit to actuate said operating device for said relative forward-to-rearward placement of said backing roll.

17. Apparatus for finishing flat sheet stock, comprising a rotatively driven abrasive supporting member, means for feeding the stock flatwise past said member in a plane paralleling said drive axis for a finishing operation by said member on said stock, a backing roll rotatable on an axis paralleling said drive axis to sustain said stock during said finishing operation, a control mechanism including means to control a relative displacement of said member and backing roll during the stock feeding in an initial relative position in which the backing roll axis is forward of the drive axis of said member in respect to the direction of feed of the said stock, and then to a relative position in which said backing roll axis is in a more rearward position on the opposite side of said drive axis as finishing proceeds, said control means comprising an operating device to effect said control displacement, a photoelectric unit adapted to be operated in response to alteration of its beam by passage of the leading and trailing edges of said sheet, and means responsive to said operation of said unit to actuate said operating device to effect said relative forward-to-rearward displacement of said backing roll, and then to restore said initial relative position of :said member and backing roll.

18. Apparatus for finishing flat sheet stock, comprising a rotatively driven abrasive supporting member, first and second driven means on opposite respective sides of the axis of drive of said member for feeding the stock fiatwise past said member in a plane paralleling said drive axis for a finishing operation by said member on said stock, a backing roll rotatable on an axis paralleling said drive axis to sustain said stock during said finishing operation, a control mechanism including means to control a relative displacement of said member and backing roll during the stock feeding in an initial relative position in which the backing roll axis is forward of the drive axis of said member in Ifispeqt to the direction of feed of the said stock, and then to a relative position in which said backing roll axis is in a more rearward position on the opposite side of said drive axis as finishing proceeds, said control means comprising an operating device to effect said control displacement, a photoelectric unit on the side of said rotatively driven member adjacent said first feed means and adapted to be operated in response to alteration of its beam by passage of the leading and trailing edges of said sheet, and means responsive to said operation of said unit to actuate said operating device to effect said relative forward-to-rearward displacement of said backing roll, and then to restore said initial relative position of said member and backing roll.

19. Apparatus for finishing flat sheet stock, comprising a rotatively driven abrasive supporting member, first and second driven means on opposite respective sides of the axis of drive of said member for feeding the stock fiatwise past said member in a plane paralleling said drive axis for a finishing operation by said member on said stock, a backing roll rotatable on an axis paralleling said drive axis to sustain said stock during said finishing operation, a control mechanism including means to control a relative displacement of said member and backing roll during the stock feeding in an initial relative position in which the backing roll axis is forward of the drive axis of said member in respect to the direction of feed of the said stock, and then to a relative position in which said backing roll axis is in a more rearward position on the opposite side of said drive axis as finishing proceeds, said control means being adapted to effect a reversing relative displacement of said drive and roll axes in timed relation to a reversal of drive of said feed means, and comprising an operating device to effect said control displacement, a photoelectric unit on the side of said rotatively driven member adjacent said first feed means and adapted to be operated in response to alteration of its beam by passage of the leading and trailing edges of said sheet, and means responsive to said operation of said unit to actuate said operating device to effect said relative forward-to-rearward displacement of said backing roll, and then to restore said initial relative position of said member and backing roll, and a further photoelectric unit on the side of said rotatively driven member adjacent said second feed means, said further photoelectric unit being operable in response to alteration of its beam upon passage of said sheet past said further photoelectric unit, and means responsive to operation of said further photoelectric unit to actuate said operating device to effect a relative displacement of said backing roll for a further finishing operation.

20. Apparatus for finishing flat sheet stock, comprising a rotatively driven abrasive supporting member, first and second driven means on opposite respective sides of the axis of drive of said member for feeding the stock flatwise past said member in a plane paralleling said drive axis for a finishing operation by said member on said stock, a backing roll rotatable on an axis paralleling said drive axis to sustain said stock during said finishing operation, a control mechanism including means to control a relative displacement of said member and backing roll during the stock feeding in an initial relative position in which the backing roll axis is forward of the drive axis of said member in respect to the direction of feed of the said stock, and then to a relative position in which said backing roll axis is in a more rearward position on the opposite side of said drive axis as finishing proceeds, said control means being adapted to effect a reversing relative displacement of said drive and roll axes in timed relation to a reversal of drive of said feed means, and comprising an operating device to effect said control displacement, at photoelectric unit on the side of said rotatively driven member adjacent said first feed means and adapted to be operated in response to alteration of its beam by passage of the leading and trailing edges of said sheet, and means responsive to said operation of said unit to actuate said operating device to efiect said relative forward-to-rearward displacement of said backing roll, and then to restore said initial relative position of said member and backing roll, and a further photoelectric unit on the side of said rotatively driven member adjacent said second feed means, said further photoelectric unit being operable in response to alteration of its beam upon passage of said sheet past said further photoelectric unit, and means responsive to operation of said further photoelectric unit to actuate said operating device to effect a relative displacement of said backing roll for a further finishing operation, said control mechanism including means References Cited by the Examiner UNITED STATES PATENTS 590,836 9/1897 Hayes. 1,998,770 4/ 1935 Shulte 51-76 2,925,691 2/1960 Kibble 5178 LESTER M. SWINGLE, Primary Examiner. 

5. IN FLAT STOCK FINISHING APPARATUS OF THE TYPE HAVING A ROTATIVELY DRIVEN ABRASIVE SUPPORTING MEMBER, MEANS TO FEED THE STOCK PAST SAID MEMBER IN A PLANE PARALLELING THE AXIS OF ROTATIVE DRIVE OF THE LATTER FOR A FINISHING OPERATION ON SAID STOCK BY SAID MEMBER, AND A ROTATIVE BACKING ROLL TO SUSTAIN SAID STOCK AGAINST SAID MEMBER DURING SAID FEED AND FINISHING OPERATION, THE IMPROVEMENT COMRPISING MEANS OPERATING IN TIMED RELATION TO THE FEED OF THE STOCK TO MOVE SAID BACKING ROLL TO AND FROM A POSITION IN WHICH THE BACKING ROLL AXIS IS FORWARD RELATIVE TO THE DRIVE AXIS OF SAID MEMBER IN RESPECT TO THE DIRECTION OF FEED OF THE STOCK. 